NASA's Heliophysics Gallery

There have been few changes since the 2017 Earth-Orbiting Heliophysics Fleet. RHESSI, TWINS, and STEREO-B have been decommissioned, while GOLD and Parker Solar Probe have been added. As of fall 2018, here's a tour of the NASA Heliophysics fleet from the near-Earth satellites out to the Voyagers beyond the heliopause.

Energetic events at the Sun can reverberate around the solar system. This visualization combines data from particle detectors around the solar system with an Enlil simulation of multiple coronal mass ejections (CMEs) in early September 2017. The Enlil model extends from 0.1 astronomical units (AUs) from the Sun (this is reponsible for the empty region around the Sun at the center of the system) out to 5 AUs.

The next missions scheduled for detailed studies of the Sun and solar atmosphere are Parker Solar Probe and Solar Orbiter. Parker Solar Probe moves in a highly-elliptical orbit, using gravity-assists from Venus to move the orbit perihelion closer to the Sun with each pass. The goal is to get the spacecraft to fly through the corona at a distance of 9.5 solar radii. Primary science operations are conducted when the spacecraft is within 0.25 astronomical units (AUs) from the Sun, so that portion of the orbit is colored red. The nominal end of mission for Parker Solar Probe is 2025, so the orbit fades away after that year. Solar Orbiter uses Earth and Venus gravity assists to move into a relatively circular orbit, inside the orbit of Mercury for monitoring the Sun. The primary science operations for Solar Orbiter are conducted when the spacecraft is within 0.5 AUs from the Sun.

The Magnetospheric Multiscale (MMS) mission consists of four identical satellites that traverse various regions of Earth's magnetosphere measuring the particles and electric and magnetic field which influence them.

This is a visualization of the Equatorial Fountain process in the ionosphere, whereby ions are driven away from the equator forming ion density enhancements to the north and south of the equator.

A basic view of the orbit for GOLD (Global-scale Observations of the Limb and Disk). This mission will conduct measurements of ionospheric composition and ionization better understand the connection between space weather and its terrestrial impacts. In this visualization, we present GOLD in geostationary orbit around Earth. The colors over Earth represent model data from the IRI (International Reference Ionosphere) model of the density of the singly-ionized oxygen atom at an altitude of 350 kilometers. Red represents high density. The ion density is enhanced above and below the geomagnetic equator (not perfectly aligned with the geographic equator) on the dayside due to the ionizing effects of solar ultraviolet radiation combined with the effects of high-altitude winds and the geomagnetic field. In the latter half of the visualization, the viewing fields of the GOLD instrument are displayed. GOLD has an imaging spectrometer (green) that periodically scans the disk of Earth with additional higher-resolution scans of the dayside limb.

When energetic particles are injected into Earth's radiation belts, perhaps by a reconnection event in Earth's magnetotail, they can become trapped by the geomagnetic field. Consequently, these energetic particles will propagate around Earth as they slowly disperse. If a satellite with particle monitors lies along the particle trajectory, the satellite can detect these particles (Prompt Electron Acceleration in the Radiation Belts). With multiple satellite detections, it is possible to approximately reconstruct the origin and path of the original particle injection. These visualizations illustrate the results of this reconstruction applied to a series of particle injections detected by multiple satellites on April 7, 2016.

The ICON (Ionospheric Connection Explorer) satellite orbits Earth at an altitude of 575 kilometers. In this visualization, we show the ICON spacecraft with the fields-of-view of four instruments for measuring the properties of the ionosphere.

There have been few changes since the 2015 Earth-Orbiting Heliophysics Fleet. As of summer 2017, here's a tour of the NASA Heliophysics fleet from the near-Earth satellites out to the Voyagers beyond the heliopause.

During the solar eclipse on August 21, 2017, the Moon's shadow will pass over all of North America. The path of the umbra, where the eclipse is total, stretches from Salem, Oregon to Charleston, South Carolina. This will be the first total solar eclipse visible in the contiguous United States in 38 years.

During the solar eclipse on August 21, 2017, the Moon's shadow will pass over all of North America. The path of the umbra, where the eclipse is total, stretches from Salem, Oregon to Charleston, South Carolina. This will be the first total solar eclipse visible in the contiguous United States in 38 years.

Since their discovery at the dawn of the Space Age, Earth's radiation belts continue to reveal new complex structures and behaviors. During a particularly intense event in late June 2015, the inner edge of the region of trapped electrons moved closer to Earth. As the region retreated outward, it left behind a population of high-energy electrons forming another radiation belt inside the L=2 shell (The 'L-shell' value identifies a field line in a magnetic dipole. The numerical value corresponds to the furthest distance from Earth in Earth radii, in this case two Earth radii). This flux of high-energy electrons persisted considerably longer than expected, the relativistic electrons slowly leaking away. It took over a year for the relativistic electron flux in the belt to decline below the level of detectability for the instruments on the Van Allen Probes. The 3-dimensional radiation belt model in the visualizations above was constructed by propagating electron flux measurements, corresponding to a given time and distance from Earth measured by the Van Allen Probes, along a 3-dimensional structure of magnetic dipole field lines.

The STEREO mission has been in operation for 10 years.

On March 17, 2016, Van Allen Probe A detected a pulse of high energy electrons in the radiation belts, generated by the impact of a recent coronal mass ejection striking Earth's magnetosphere. The gradient drift speed of the electron pulse was high enough, that it propagated completely around Earth and was detected by the spacecraft again as the pulse spread out in the radiation belt. Because the particles have a range of energies, the pulse spread out as it moved around Earth, generating a weaker signal the next time it hit the spacecraft.

While the sun is well known as the overwhelming source of visible light in our solar system, a substantial part of its influence is driven by some aspects less visible to human perception - the magnetic field. Most of the solar photosphere has a magnetic field intensity of a few gauss while the active regions which form around sunspots can have magnetic fields of a few thousand gauss. Modern space-based instruments such as HMI (Helioseismic and Magnetic Imager) on the Solar Dynamics Observatory (SDO) enable us to measure the intensity of the magnetic field at the visible surface of the sun. In this visualization, the sphere represents the solar photosphere, with neutral grey indicating a magnetic field of near zero intensity, black representing a magnetic field pointing INTO the sun (south or negative polarity) and white representing a magnetic field pointing OUT of the sun (north or positive polarity). We see that these magnetic regions often appear in nearby pairs of opposite polarities - which in visible light would often correspond to a pair of sunspots. Using this measured magnetic field on the photosphere, combined with mathematical models based on Maxwell's equations and plasma physics, we can construct how the magnetic field would look above the photosphere. Here, the white magnetic field lines are considered 'closed'. The move up, and then return to the solar surface. We often see these closed lines associated with pairs of active regions on the sun. The green and violet lines represent field lines that are considered 'open'. Green represents positive magnetic polarity, and violet represents negative polarity. These field lines do not connect back to the sun but with more distant magnetic fields in space. Here we build one of the simpler magnetic field models, called Potential Field Source Surface or PFSS, to construct how the magnetic 'lines of force' might look above the sun. The PFSS model represents the simplest and most steady magnetic field possible, though here we sample the field each day to illustrate the slow changes of the magnetic structure over time, in this case between January 1, 2011 through December 30, 2014. This camera view is fixed in Carrington Heliographic coordinates, so it moves with an 'average' solar rotation value with a period of 25.38 days. The solar equator moves faster than this, and high latitudes move slower. This makes active regions near the equator appear to move to the right (on average) while higher latitude regions move leftward. Some might note that this model looks rather different than an earlier version The Sun's Magnetic Field. In the earlier version, we were interested in the magnetic field structure significantly above the solar surface and so the model is examined favoring the field lines that reach high above the photosphere. In the model presented here, we are more interested in the magnetic field around the solar active regions, so we examine the model much closer to the photosphere, which favors magnetic field lines clustered around the active regions. An artifact in this visualization is a 'jump' of change that sweeps through the magnetic loops about once per month based on the timestamp in the lower left corner. This is an artifact of the fact that these types of magnetic field measurements can only be done on one side of the sun at a time. As the sun rotates, the features disappear over the limb and new ones appear on the opposite limb. While on the far-side of the sun from Earth, we have no direct measurements. However, we do have models that can simulate the slow changes in the field while not visible from Earth (described in the science paper Photospheric and heliospheric magnetic fields by Carolus J. Schrijver and Marc L. De Rosa). The 'jump' is created at the seam where the less accurate model gets overwritten by newer data.

Everyone likes to check the weather in a far away destination before they travel there. This is especially true for spaceflight, where the destination may be where no one has gone before. The mission of New Horizons to Pluto provided an opportunity to test our current space weather models, pushing them to the limit. This visualization presents the results from an Enlil model run, just one of the many space weather models being tested through the Community-Coordinated Modeling Center (CCMC) at NASA's Goddard Space Flight Center as part of the "New Horizons Flyby Modeling Challenge". This visualization presents a slice of the data through the ecliptic plane, the plane in which the planets of our solar system orbit. Because Pluto is a bit above this plane, the orbit is projected into the ecliptic plane of the data, as is the trajectory of the New Horizons probe. Three different variables are presented from the model - temperature, density, and pressure gradient, simultaneously, using the red, green and blue color channels of the color image. The density of the solar wind (green) flowing outward from the sun decreases as it spreads out. The temperature stays roughly constant as the solar wind material spreads through the solar system. We see the Parker spiral imprinted on the outflow from the spinning sun, much like the outflow from a spinning water sprinkler. We also see the strong density gradients (blue) created by coronal mass ejections and other shocks, propagating outward from the sun in the solar wind. We can observe regions of interesting interactions when the three primary colors of the basic variables combine to enhance the color, represented in the tricolor diagram below. White represents a hot, dense shock, while cyan (blue-green) represents a dense shock (usually visible close to the sun), magenta (purple) represents a hot, low-density shock, while yellow indicates hot and dense material, again usually close to the sun.

A listing of all the visualizations showing SOHO and its discovery of comets.

The Interface Region Imaging Spectrograph (IRIS) explorer is one of the latest imaging spectrographs developed for NASA missions, this one designed for exploring the energization process in the solar chromosphere at higher resolution than previously possible. An imaging spectrograph not only takes an image of the region of interest, but also has a small slit in the imager (seen as a dark line about half-way across the image) which passes a thin ribbon of light to a spectroscope. The spectroscope spreads the light out in its component frequencies or spectrum. Monitoring of specfic spectral lines provides additional information on the velocity (and therefore temperature) of plasma in the observed region. In the visualization presented here, the IRIS slit-jaw imager (SJI) takes images with two different filters, one at 1330 Angstroms (gold color table), the other at 1400 Angstroms (bronze color table), and these images are displayed overlaying corresponding imagery from the Solar Dynamics Observatory (SDO) 304 Angstrom filter (grayscale). The spectra, in this case a closeup view on the 1403 Angstrom line from 3-times ionized silicon (designated Si IV), is presented on a semi-transparent plane perpendicular to the images, at the position of the slit in the imager. This allows us to see correlations between features in the images and spectra. For example, some of the bright spots in the image correlate to wider regions along the line suggesting higher temperatures and/or velocities of the plasma emitting the spectral line. To better examine the region, the instrument also scans the slit over the region of interest, collecting multiple spectra. This allows scientists to compare and correlate structures seen in images with speeds and temperatures of the plasma. Imaging spectrographs have been flown on other NASA missions, such as the STIS instrument on the Hubble space telescope.

There've been a few changes since the 2013 Earth-Orbiting Heliophysics Fleet. As of Spring of 2015, here's a tour of the NASA Near-Earth Heliophysics fleet, covering the space from near-Earth orbit out to the orbit of the Moon.

The satellite orbits are color coded for their observing program:

• Magenta: TIM (Thermosphere, Ionosphere, Mesosphere) observations
• Yellow: solar observations and imagery
• Cyan: Geospace and magnetosphere
• Violet: Heliospheric observations

Near-Earth Fleet:

• Hinode: Observes the Sun in multiple wavelengths up to x-rays. SVS page
• RHESSI : Observes the Sun in x-rays and gamma-rays. SVS page
• TIMED: Studies the upper layers (40-110 miles up) of the Earth's atmosphere.
• CINDI: Measures interactions of neutral and charged particles in the ionosphere.
• SORCE: Monitors solar intensity across a broad range of the electromagnetic spectrum.
• AIM: Images and measures noctilucent clouds. SVS page
• Van Allen Probes: Two probes moving along the same orbit esigned to study the impact of space weather on Earth's radiation belts. SVS page
• TWINS: Two Wide-Angle Imaging Neutral-Atom Spectrometers (TWINS) are two probes observing the Earth with neutral atom imagers.
• IRIS: Interface Region Imaging Spectrograph is designed to take high-resolution spectra and images of the region between the solar photosphere and solar atmosphere.

Geosynchronous Fleet:

• SDO: Solar Dynamics Observatory keeps the Sun under continuous observation at 16 megapixel resolution.

Geospace Fleet:

• Geotail: Conducts measurements of electrons and ions in the Earth's magnetotail.
• Magnetospheric Multi-scale (MMS): This is a group of four satellites which fly in formation to measure how particles and fields in the magnetosphere vary in space and time. SVS page
• THEMIS: This is a fleet of three satellites to study how magnetospheric instabilities produce substorms. Two of the original five satellites were moved into lunar orbit to become ARTEMIS. SVS page
• IBEX: The Interstellar Boundary Explorer measures the flux of neutral atoms from the heliopause.

Lunar Orbiting Fleet

• ARTEMIS: Two of the THEMIS satellites were moved into lunar orbit to study the interaction of the Earth's magnetosphere with the Moon.

Major changes with earlier versions:

• MMS added
• GOES satellites removed
• Cluster satellites removed
• Camera moves around the night-side of Earth
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On July 12, 2012, at 12:11 EDT, a solar reconnection event initiated a solar flare, and then a coronal mass ejection (CME) (see Big Sunspot 1520 Releases X1.4 Class Flare). Later that month, after solar rotation had carried it so it was directed away from Earth, the same active region would launch a much larger event (see The Carrington-Class CME of 2012).

The near-Earth space enviroment is a complex interaction between Earth's magnetic field, cool plasma moving up from Earth's ionosphere, and hotter plasma coming in from the solar wind. This interactions combine to maintain the radiation belts around Earth. Plasma interactions can generate sharply delineated regions in these belts. In addition to the inner and outer radiation belts, the cooler plasma of the plasmasphere interacts so that it keeps out the higher-energy electrons from outside its boundary (called the plasmapause). In this visualization, the radiation belts (rainbow-color) and plasmapause (blue-green surface) surround Earth, its structure largely determined by Earth's dipole magnetic field (represented by cyan curved lines). The radiation belt is sliced open, simultaneously revealing representative confined charged particles spiraling around the magnetic field structure. Yellow particles represent negative-charged electrons, blue particles represent positive-charged ions. However, if realistically scaled for particle mass and energies, the spiral motion would not be visible at this distance so particle masses and size scales are adjusted to make them visible. The inner blue-green plasmapause boundary is then sliced open to reveal more of the inner structure of the radiation belts, including the innermost belt.

The BIG coronal mass ejection that missed Earth.

The ionosphere is layer of the upper atmosphere (60-1000 km up) where the neutral atoms and molecules of the lower atmosphere transition to the plasma of space.

Orbits and trajectories of many missions observing the Sun and the near-Earth environment.

The sun is always changing and NASA's Solar Dynamics Observatory is always watching. Launched on Feb. 11, 2010, SDO keeps a 24-hour eye on the entire disk of the sun, with a prime view of the graceful dance of solar material coursing through the sun's atmosphere, the corona.

SDO, the Solar Dynamics Observatory, images the entire sun at 4096x4096 resolution in multiple wavelengths every 12 seconds. The selection below represents some of the best options for full-disk slow rotation. The 4k content is available for download as frame sequences, and, in some cases, as ProRes video. These files are large and will take a long time to download.